| Purpose: Intervening the pubertal status epilepticus(SE) with vascular endothelial growth factor(VEGF), by exploring the changes of neuron-specific enolase(NSE) and glial fibrillary acidic protein(GFAP) in hippocampus at different time points, in order to investigate the neuroprotective effect of VEGF on the SE.Methods: 124 of postnatal 14-day-old(P14) healthy SD rats were divided randomly into four groups: normal control group(CONT group, n=31), kainic acid control group(KA control group, n=31), sham operation group(PBS intervention group, n=31) and VEGF intervention group(VEGF treatment group, n=31). When P14, VEGF intervention group rats intracerebroventricular injection of VEGF(concentration 0.02μg/μl, the dose 2μl, namely VEGF 0.04μg), PBS intervention group rats intracerebroventricular injection of the same dose of PBS, the other two groups without intracerebroventricular injection. When P15, VEGF intervention group, PBS intervention group, KA control group were injected with kainic acid(concentration of 2mg/ml, dose of 1.25ml/kg, namely kainic acid 2.5mg/kg) to establish the model of status epilepticus, CONT group was injected with the same dose of normal saline. One rat was selected randomly in different groups at the 1st day after the model established to identify the model by HE staining. Six rats were selected randomly in different groups at the 1st, 3rd, 7th, 14 th, 21 th days after the model established to form P16 subgroup(n=6), P18 subgroup(n=6), P22 subgroup(n=6), P29 subgroup(n=6) and P36 subgroup(n=6). To measure the expression of NSE, GFAP in hippocampal tissue by immunoblotting technique(Western blot).Results: 1. The behavioral characteristics of pubertal status epilepticus rats intervened by kainic acid: After intraperitoneal injection of kainic acid about 2-3min, the rats started seizures, first manifested as irritability, staring, Saotou action, wet dog-like movements, paroxysmal run, then limb myoclonus, seizures, and even generalized tonic-clonic seizures, severe death. The modeling failure rate was 5.10%, and the mortality rate was 4.08%.2. The HE staining result in hippocampal CA3 region: In CONT group, the pyramidal cells in hippocampal CA3 region were neat, clear and complete cellular structure. In KA control group and PBS intervention group, the neurons were significantly smaller, arrangement sparse, irregular, serious damage can be seen a large number of neuronal degeneration and death. In VEGF intervention group, the neuronal cells were less degeneration and death, the cell body is slightly larger, slightly arranged rules, visible glial cells mild hyperplasia, copared to KA control group and PBS intervention group.3. Western Blot results:(1) The expression of NSE in hippocampus: At the 1st day after SE, the NSE expression of KA control group and PBS intervention group had reached a high level, which reached its peak at the 3rd day, remained at a high level during the week, and still significantly higher than CONT group at the 14 th day. The NSE expression level of VEGF intervention group was declined to KA control group and PBS intervention group at each time point after SE, and was most obvious at the 3rd day, though still higher than CONT group.(2) The expression of GFAP in hippocampus: At the 1st day after SE, the GFAP expression of KA control group and PBS intervention group began to increase, which were significantly higher than CONT group and reached its peak at the 7th day. The GFAP expression of VEGF intervention group were still higher than CONT group, but has declined to KA control group and PBS intervention group at the 3rd,7th,14 th day,and the most obvious difference appeared at the 7th day.Conclusion: 1. Intraperitoneal injection of kainic acid can build pubertal status epilepticus model in SD rats, and has a high modeling success rate.2. After early phase of status epilepticus, the hippocampal neurons and glial cells of pubertal rats are damaged.3. VEGF has a protective effect on hippocampal damage caused by status epilepticus in pubertal rats. |
PDF Full Text Request